1. Field of the Invention
The present invention relates to an apparatus for measuring response time and a method of measuring response time using the same, and more particularly, to an apparatus for measuring response time and a method of measuring response time using the same, which measures response time in an area that is less than a pixel size.
2. Description of the Related Art
Generally, a liquid crystal display (LCD) is used as flat panel display because it is relatively thin, light weight, and consumes less power than a cathode ray tube (CRT). As the liquid crystal display is applied to the display field of a display apparatus that displays moving images, a response time of liquid crystals is important.
A response time of liquid crystal includes a rising time and a falling time. The rising time is defined as a time that leads 10% to 90% of a permeation ratio at a normally black mode. A falling time is defined as a time that leads 90% to 10% of a permeation ratio at a normally black mode. Slow response time of liquid crystal causes motion blurring on the liquid crystal display and affects the quality of a display device adversely.
A multi-domain mode, such as vertical alignment (VA), has recently been applied to the liquid crystal display to improve a viewing angle of the liquid crystal display. The multi-domain mode has various response times even in one-pixel showing a color because the one-pixel is divided into multiple domains. Overall response time of the multi-domain mode is determined by the slowest response time of the multiple domains. Thus, it is important to measure response time in the area that is less than a pixel size to determine which domain has the slowest response time.
A conventional apparatus for measuring response time uses a photo multiplier or a photo diode. Such conventional apparatus for measuring response time measures an overall luminance of the display screen. Thus, the apparatus may not measure response time in the area that is less than the pixel size.